A candle flame is a beautiful little light that glows brightly in the dark as a symbol of hope and truth. And yet, behind the symbolic importance of the candle, there is a chemical truth that is inescapable. It is the life of the fire and the nature of the candle, and determines if the flame lights up and how long it lasts when it does.
A candle is made up of a wick, which is embedded in some kind of fuel that will burn when it comes into contact with a flame. Before lighting a candle, the wick is dipped into this fuel to light it. When a fire comes in contact with a fuel-soaked wick, it heats the fuel and then vaporizes it, allowing it to combine with oxygen in the air. The result is a fire powerful enough to keep burning, without consuming its fuel too quickly to be useful.
The stasis that allows a flame to remain intact comes from the fact that the heat of the flame on the wick is sufficient to melt the fuel or wax of the candle. Once the fuel has been reduced to its liquid form, it can move up the candle wick through a process known as capillary action. Once the wax fuel is in the wick, it can supply the flame with the raw materials it needs to keep burning bright enough to melt even more wax.
As the fuel burns, the candle shortens. This means that the wax has to travel further up the wick to feed the candle flame. When the wick is too long to carry enough fuel along its length to keep the flame burning, the extended portion of the wick burns out. This allows the candle wick to shrink steadily with decreasing candle size. It also allows a candle to regulate its temperature and energy, so they don’t get out of control.
When you look at a candle flame, you will notice that it has different colors in different places. In the center, a candle flame will often be blue, indicating that it is warmer there. This is because the flame in the center separates the hydrogen from the fuel and burns it to form water vapor. When the candle is yellow and brighter, it represents the area where the remaining carbon is oxidized to form carbon dioxide.
When you look at a candle, what do you see? It is something complex and wonderful that can stir our emotions and inspire our souls. But it is also a process, of constant renewal and cyclical stability. Only in balance can the flame be maintained.